<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK IT ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006-2014 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------

namespace Think\Db\Driver;

use Think\Db\Driver;

/**
 * mysql数据库驱动 
 */
class Mysql extends Driver
{

  /**
   * 解析pdo连接的dsn信息
   * @access public
   * @param array $config 连接信息
   * @return string
   */
  protected function parseDsn($config)
  {
    $dsn  =   'mysql:dbname=' . $config['database'] . ';host=' . $config['hostname'];
    if (!empty($config['hostport'])) {
      $dsn  .= ';port=' . $config['hostport'];
    } elseif (!empty($config['socket'])) {
      $dsn  .= ';unix_socket=' . $config['socket'];
    }

    if (!empty($config['charset'])) {
      if (version_compare(PHP_VERSION, '5.3.6', '<')) {
        // PHP5.3.6以下不支持charset设置
        $this->options[\PDO::MYSQL_ATTR_INIT_COMMAND]    =   'SET NAMES ' . $config['charset'];
      } else {
        $dsn  .= ';charset=' . $config['charset'];
      }
    }
    return $dsn;
  }

  /**
   * 取得数据表的字段信息
   * @access public
   */
  public function getFields($tableName)
  {
    $this->initConnect(true);
    list($tableName) = explode(' ', $tableName);
    if (strpos($tableName, '.')) {
      list($dbName, $tableName) = explode('.', $tableName);
      $sql   = 'SHOW COLUMNS FROM `' . $dbName . '`.`' . $tableName . '`';
    } else {
      $sql   = 'SHOW COLUMNS FROM `' . $tableName . '`';
    }

    $result = $this->query($sql);
    $info   =   array();
    if ($result) {
      foreach ($result as $key => $val) {
        if (\PDO::CASE_LOWER != $this->_linkID->getAttribute(\PDO::ATTR_CASE)) {
          $val = array_change_key_case($val,  CASE_LOWER);
        }
        $info[$val['field']] = array(
          'name'    => $val['field'],
          'type'    => $val['type'],
          'notnull' => (bool) ($val['null'] === ''), // not null is empty, null is yes
          'default' => $val['default'],
          'primary' => (strtolower($val['key']) == 'pri'),
          'autoinc' => (strtolower($val['extra']) == 'auto_increment'),
        );
      }
    }
    return $info;
  }

  /**
   * 取得数据库的表信息
   * @access public
   */
  public function getTables($dbName = '')
  {
    $sql    = !empty($dbName) ? 'SHOW TABLES FROM ' . $dbName : 'SHOW TABLES ';
    $result = $this->query($sql);
    $info   =   array();
    foreach ($result as $key => $val) {
      $info[$key] = current($val);
    }
    return $info;
  }

  /**
   * 字段和表名处理
   * @access protected
   * @param string $key
   * @return string
   */
  protected function parseKey(&$key)
  {
    $key   =  trim($key);
    if (!is_numeric($key) && !preg_match('/[,\'\"\*\(\)`.\s]/', $key)) {
      $key = '`' . $key . '`';
    }
    return $key;
  }

  /**
   * 批量插入记录
   * @access public
   * @param mixed $dataSet 数据集
   * @param array $options 参数表达式
   * @param boolean $replace 是否replace
   * @return false | integer
   */
  public function insertAll($dataSet, $options = array(), $replace = false)
  {
    $values  =  array();
    $this->model  =   $options['model'];
    if (!is_array($dataSet[0])) return false;
    $this->parseBind(!empty($options['bind']) ? $options['bind'] : array());
    $fields =   array_map(array($this, 'parseKey'), array_keys($dataSet[0]));
    foreach ($dataSet as $data) {
      $value   =  array();
      foreach ($data as $key => $val) {
        if (is_array($val) && 'exp' == $val[0]) {
          $value[]   =  $val[1];
        } elseif (is_scalar($val)) {
          if (0 === strpos($val, ':') && in_array($val, array_keys($this->bind))) {
            $value[]   =   $this->parseValue($val);
          } else {
            $name       =   count($this->bind);
            $value[]   =   ':' . $name;
            $this->bindParam($name, $val);
          }
        }
      }
      $values[]    = '(' . implode(',', $value) . ')';
    }
    // 兼容数字传入方式
    $replace = (is_numeric($replace) && $replace > 0) ? true : $replace;
    $sql    =  (true === $replace ? 'REPLACE' : 'INSERT') . ' INTO ' . $this->parseTable($options['table']) . ' (' . implode(',', $fields) . ') VALUES ' . implode(',', $values) . $this->parseDuplicate($replace);
    $sql    .= $this->parseComment(!empty($options['comment']) ? $options['comment'] : '');
    return $this->execute($sql, !empty($options['fetch_sql']) ? true : false);
  }

  /**
   * ON DUPLICATE KEY UPDATE 分析
   * @access protected
   * @param mixed $duplicate 
   * @return string
   */
  protected function parseDuplicate($duplicate)
  {
    // 布尔值或空则返回空字符串
    if (is_bool($duplicate) || empty($duplicate)) return '';

    if (is_string($duplicate)) {
      // field1,field2 转数组
      $duplicate = explode(',', $duplicate);
    } elseif (is_object($duplicate)) {
      // 对象转数组
      $duplicate = get_class_vars($duplicate);
    }
    $updates                    = array();
    foreach ((array) $duplicate as $key => $val) {
      if (is_numeric($key)) { // array('field1', 'field2', 'field3') 解析为 ON DUPLICATE KEY UPDATE field1=VALUES(field1), field2=VALUES(field2), field3=VALUES(field3)
        $updates[]          = $this->parseKey($val) . "=VALUES(" . $this->parseKey($val) . ")";
      } else {
        if (is_scalar($val)) // 兼容标量传值方式
          $val            = array('value', $val);
        if (!isset($val[1])) continue;
        switch ($val[0]) {
          case 'exp': // 表达式
            $updates[]  = $this->parseKey($key) . "=($val[1])";
            break;
          case 'value': // 值
          default:
            $name       = count($this->bind);
            $updates[]  = $this->parseKey($key) . "=:" . $name;
            $this->bindParam($name, $val[1]);
            break;
        }
      }
    }
    if (empty($updates)) return '';
    return " ON DUPLICATE KEY UPDATE " . join(', ', $updates);
  }
}
